Did played the mission myself. And a few things crossed my mind:
1) You need a decent group of (more or less) working together to get this done. In case of all TD tanks, you get screwed. You need some " tank bunkers" to soak up the dmg, with support of TDs to help you.
2) Tier 8 is very hard to do because of a lot of tier X AI tanks.
3) Looks to me as the beginning of a storyline if you listen to the " commanders talk"
But overall, I like this " harder game". Is an improvement for the game.